1. Field of the Invention
The present invention relates to a display, and more particularly, to a plasma display panel which is provided with a dot type transparent electrode.
2. Description of the Related Art
A Plasma Display Panel(PDP), as a kind of flat display, is a display which drives independently each of cells with a gas discharge, thereby displaying a desired image.
This PDP has the advantage of remarkably reducing its thickness and weight compared with an existing display using an electron gun, since a thickness between a front substrate and a rear substrate opposite to each other can be formed below about 10 cm. In addition, because a space between barrier ribs which separate each cell can be defined widely, it is possible that the size of screen can be made to be bigger than that of liquid crystal display(LCD). Moreover, the PDP has the advantage of improving a narrow visual angle which is the largest shortcoming in the LCD.
FIG. 1 shows a partial cross-sectional view of an alternating-current PDP(AC PDP) of a conventional art.
Referring to FIG. 1, a surface-discharge PDP comprises a first substrate or front substrate 4 and a second substrate or rear substrate 1 which are provided with each inner face opposite to each other, wherein the front substrate 4 means a substrate directed toward a screen at which a viewer looks. A barrier rib is located between the rear and front substrates 1, 4. The barrier rib defines a cell or unit pixel, and has a function of preventing a crosstalk among the pixels. On the rear substrate 1 of the unit pixel which is defined by the barrier ribs, there is placed an address electrode 2 which transfers an address signal to select the unit pixels perpendiculary arranged to the drawing. A first dielectric layer 3 is positioned on the upper portion of the rear substrate 1 including the address electrode 2. Fluorescent material 10 which is selected out of red, blue, green ones is coated on the first dielectric layer 3 so as to be capable of materializing colors upon gas discharge. On the upper face of the front substrate 4 opposite to the inner face of the rear substrate 1, a discharge maintenance electrode in which a transparent electrode 5 and a data bus electrode 6 are stacked in order is placed. The transparent electrode 5 and data bus electrode 6 are arranged to be orthogonal with the arrangement direction of the barrier rib and have a stripe structure respectively. Furthermore, the data bus electrode 6 has a narrower width than that of the transparent electrode 5 (not shown), and is located on the upper portion of the transparent electrode 5. A second dielectric layer 7 and a protective layer 8 are stacked in order on the data bus electrode 6. As a result, the unit cell is defined by a pair of barrier ribs and a pair of data bus electrodes 6. A discharging space, which is defined by the protect layer 8, barrier rib 9 and fluorescent material 10, is filled with a gas 11 such as neon or xenon.
If an address signal for selecting the cell is supplied and a data signal is applied to the data bus electrode 6, the selected cells emit respectively a light by the gas discharge, whereby the PDP provided with such structure displays an image on the front substrate 4.
In order to progress a contrast ratio, as shown in FIG. 2, each of the discharging cells have to be divided into a displaying area and a non-displaying area in a plan view. However, the above mentioned PDP has a problem in that, since the discharging is also occurred in the non-displaying area upon the gas discharge for realizing the image, the entire contrast ratio is reduced. In order to solve the problem, there had been provided a method of forming the thickness of the dielectric layer to be thick, thereby restraining the gas discharge in the non-displaying area. However, there are also some problems in this method. That is, an additional process for forming the dielectric layer is necessary. And also, if the dielectric layer is coated on the non-displaying area, the discharging effect is reduced.